The Block Logo Phase 90 has found its way into many of Eddie Van Halen's recordings and countless others! It adds a shimmery velocity to lead passages or a more dramatic swoosh to muted strumming. From Pink Floyd to the Rolling Stones! Not just for guitars; it works well with bass, keyboards and even vocals. I think you can hear it on a Led Zepplin recording... on the drums! Vary the speed from a subtle, long cycle to a fast, watery warble... and myriad vintage vibrations in between. Power: Dunlop ECB003 AC Adapter or Single 9 volt battery. • MFSKU M-101 • UPC 710137006522